That also explains the shiny, ultra-soft back that's persisted into the 4th generation. My iPod 64GB 4th generation is my first Apple product since 1994, and one reason is that Apple has tended to make design choices that seemed strange to me. I had no idea the Touch's back was so delicate, and after five day's of ownership, which included resting it on a smooth desktop to sync with my PC, it's got scratches on its back, which ruins the prettiness of the shiny back. I can't think of any other product which has an aspect like this that essentially "breaks" the instant you start to use it. I mean, the Touch's slogan could be, "Look, but don't touch," or maybe it should just come with an eiderdown satin pillow to rest it on.
As for the light leak, I've got a small one on the left side near the volume buttons, and a pinpoint-sized one on the right side. I'd only ever notice it while using the Touch in the dark, which is going to be uncommon for me. The bigger issue for me is the very poor viewing angles; even very small changes in orientation cause noticeable color or contrast/brightness shifts.
So these are the things I don't like. None of them are severe enough for me to take the Touch back. The back softness and poor viewing angles are inherent to the design; they're all like that. The light leakage appears to be a very common defect, and mine is not the worst I've seen described.
These are simply the sorts of things you'll put up with if you want a Touch, which I very much do, because it's better in so many other ways than my prior Zune HD (and previous Zune generations) and other PMPs on the market. I've resisted buying an iPod until now, and I don't regret my very expensive purchase at all. The Touch is one product for which the functionality and performance of an Apple product outweigh the strange design choices and defects.
